The rhythm of theatre

Verse drama. There's an effective way to shed a thousand readers at a stroke. It's the one phrase I beg producers of my plays to omit from the publicity material. I write plays in verse because I trained as a poet, and I've been writing in loose pentameters for a quarter of a century. As Hamlet said of his imminent duel with Laertes, "I have been in continual practice", and I can write more powerfully and clearly in lines than I can in sentences. And since I, like most writers, believe I exist primarily to tell stories, I'll tell them in the best form I know. They are plays.

I trained as a poet in Boston, where I enrolled after university in what I thought of as the great joke of the American creative writing industry. But on the plane I made a note to have a look at the work of this West Indian chap Walcott, who at some ludicrous hour of the morning was going to "teach me poetry". Me? I'd had poems in national magazines. At 22! He looked at one of them and tore it into pieces. He told me I was a real poet who knew absolutely nothing.

In the morning he'd talk to the class for two hours about poetry. Then we'd have lunch and walk up Commonwealth Avenue to his theatre, and he'd talk to us for three hours about theatre. We'd have Milton or Yeats or Lowell ringing in our ears as we scanned that deep black space. This seemed very natural to me, as the best days of one's life tend to at the time, but I've discovered over 10 years of teaching poetry in the US that it's pretty unusual to have the creative writing people and the theatre faculty housed within the same square mile, let alone in the hands of one great practitioner.

TS Eliot admitted he embarked on writing Murder in the Cathedral believing that certain subjects - the mythical, the remote historical - were "suitable for verse", because audiences at such plays "expect poetry to be in rhythms which have lost touch with colloquial speech". But he didn't think that for long: "What we have to do is bring poetry into the world in which the audience lives and to which it returns when it leaves the theatre; not to transport the audience into some imaginary world totally unlike their own, an unreal world in which poetry can be spoken."

I think poets have nothing to offer the stage at all, unless they jettison everything they know at the door. Nothing they are good at is going to help anyone there: their metaphors kill momentum, their obscurities blur the action. And if poets can't tell stories they should exit the premises.

But the stage has everything to offer them. Above all it has actors, who understand rhythm, coherence, balance, breath. Breath is the key to everything. A poem that doesn't acknowledge the limitations and strictures of the breath will fail because it is failing to make a human sound (where human can be both adjective and noun, sound both noun and verb). Most new poetry is unmemorable not because it's obscure, or self-absorbed, or trivial - terrific poems can be written in all those ways - but because most young poets have lost their sense of human sound. Or they know what it is, but can't write the shape of it. All the wit and learning in the world can't compensate for an inability to render persuasively the distinct voice of an actual breathing person.

But it's not just breath. The pulse of the bloodstream, the knock and sway of walking, the time it takes to turn the gaze from here to there, or to focus the eyes from far to near, or from memory to eyesight - all these things can be rendered in lines of verse or - crucially, for this is where verse leaves prose behind - the spaces between them.

I'm no nostalgist for Palgrave's Golden Treasury. I think the middle of the 20th century was the great age of English poetry. But I believe certain elements that were radical in their time have calcified into an orthodoxy. Somewhere along the line, poetry got confused with history, as if America's bloody and failing slog towards democracy and civil rights equated to a sloughing-off of such royalist-imperialist trappings as rhyme, stanzas, metre and meaning.

And the greatest tool in the service of this art is the line of five beats, the pentameter, which was no more nor less natural in the day of Shakespeare than it is today. It simply seems to hold as an approximation of the breath, and, as such, serves as a metaphor for the experience of a moment. Neither verse nor prose has found a better one.

While so many spent the 20th century gleefully breaking that line, as every generation renewed the licence to be revolutionary, it survived, not on stage, but modulated by the likes of Frost and Edward Thomas, Wallace Stevens, Larkin, Lowell, Bishop, to a poetic line as miraculously flexible as it has ever been. But still the new radicals come, the theorists, the cutting-edgers, breaking the old forms again, shuddering at the thought of a readable human profile, asking us to guess what's going on in their complicated minds ...

Well, there's nothing going on in my mind. Nothing but making up stories and making up people to tell them. Making up the ways they speak, so that none of them sounds like I do. Making up the ways they think. Craning my head forward like an old man while I write, to see what consonants that makes possible, or slouching back like a lover suddenly left behind, to see how long the vowels last ... Making people up, hemming them into their mortality, giving them this many words and no more, letting what they'll never know just whistle about them. Whether or not I succeed, lines of verse can do this. Which is why verse should be on stage. Which is why I sometimes think it's all that should be on stage.

· Glyn Maxwell's Plays One (The Lifeblood, Wolfpit, The Only Girl in the World) is published by Oberon; his last book of poetry was The Sugar Mile (Picador).